Drawbench



Nov. 17, 1953 A. KREIDLER 2,659,480

DRAWBENCH Filed Aug. 10, 1951 2 Sheets-Sheet 2 J/V/f/V/W'? ale ad myPatented Nov. 1?, 1953 'l'TES PATENT FFICE Claims priority, applicationGermany August 16, 1950 6 Claims.

l' -his invention concerns draw benches used during drawing operationson rods and tubes.

A fault that often in the operation of draw-benches is that during thedraw ng operation the teeth on the jaws of the drawing tongs bite sodeeply int t e rod or tube being drawn that it is not immeo. elyreleased when the tongs are opened. She effort then required to withdrawthe rod or tube from the tongs involves ex cessive expenditure of timeand energy. In those draw-benches wherein, on conclusion of the drawingoperation, the carriage deviates from the line or" pull during itsreturn to the starting position, the danger arises that the rod or tubewill be bent and the draw-bench damaged.

The present invention avoids these disadvantages by the provision of anejector for the drawn rod or tube, mounted on the longitudinally movingtongs, and. a stop or similar device located on a fixed part of thedraw-bench and designed to move the ejector into its operative positionat the end of the drawing operation. For this purpose the ejector ismounted on the tongs in such a manner that it can enter between theopened jaws and eject the rod or tube. An especially suitable ejectorfor this purpose comprises a bell-crank lever, one arm of which (theejector arm) passes between the jaws of the tongs when the other (theoperating arm) strikes the stop.

It advantageous to combine a safety device with the ejector stop. Thestop may be spring loaded, so as to be displaceable by the operating armof the ejector in case of excessive resistance the rod or tube, shouldthe latter become jammed on the tongs. The stop then serves to interruptor disconnect the drive from the draw-bench and so bring it to astandstill. This be effected, for example, by means of an electric swit.1 which is turned to the off position by the movement of the stop, sothat the machine brought to a halt whenever the ejector fails to ejectthe rod or tube from the tongs, and consequently no damage can becaused.

The invention will be described further, by way of example withreference to the accompanying drawings in which:

Figs. 1 and 2 depict in sectional elevation, and in sectional plan viewon the line IIII of Fig. 1 respectively, one embodiment of theinvention;

and

Figs. 3 and 4 show an alternative e ector rnechanism and, an emergencystop in more detail, Fig. 3 being insectional end view and Fig. 4 beinga. plan view on the line IV--IV of Fig. 3.

On the upper longitudinal girders l of the draw-bench, the carriage 2runs on rollers 3. For the sake of clarity, the draw-chain is not shown.Firmly secured to the carriage are the tongs E which are open top andbottom and within which are inserted obliquely the jaws 5. An operatinglever 5 pivoted on the tongs serves in known manner to open and closethe tongs by longitudinal displacement of the jaws 5. An ejector leverl, which is rigidly mounted on'the shaft 8, is free to move within thespace between the tongs. The shaft 8 is pivoted between the lower partof the tongs, and rigidly mounted upon it, outside the tongs, is theoperating lever ii which abuts against a lateral projection H on thetongs, under the force of a tension spring so, so that the operatinglever 9 is downwardly directed whilst the ejector lever 7 lies in ahorizontal position beneath the lower edge of the jaws of the tongs. Thestop I2, which is secured laterally on to one of the girders of thedrawbench, projects into the path of the operating lever 9. (Figs. 1 and2.)

At the conclusion of a drawing operation, angular displacement of thelever 6 causes the tongs t to be opened by withdrawal of the jaws As thecarriage 2 advances further, the lever B strikes the stop 1 2 and isdisplaced into the position indicated by chain-dotted lines in Fig. 1,thus causing the ejector lever 7 (the other arm of the virtualbell-crank lever l, 9) to be displaced in an upward direction betweenthe open jaws 5 and to strike against the rod or tube, if this has notalready automatically released itself from the tongs, thus forcing itupward and out of the tongs.

In the arrangement illustrated in Figs. 3 and 4, the stop 12 constitutesone arm of a lever pivoted at M in. a bearing l3 attached to the girderI, the other arm of whialever I5 abuts, under the force of acomparatively strong tension spring to, against a square-headed bolti'l.- The actuating member of the driving-motor switch I8 is locatedwithin the orbit of the arm it of the lever I 2, l5.

If the jaws 5 have bitten so deeply into the rod or tube as to preventits being ejected by the ejector 7, the lever 9 causes the lever l2; l5to be displaced into the position indicated by chain-dotted lines inFigure 4, whereupon the arm 15 actuates the switch I8, with the resultthat the driving motor is switched off and the machine stops, and nodamage is caused to its components.

It is of course understood that the lever l5, may

be replaced b other suitable means, such as, for example, alongitudinally displaceable slidebar, and also could be arranged to stopthe machine by disconnecting a mechanical coupling.

I claim:

1. A draw bench comprising in combination a fixed base, a carriageadapted to be moved longitudinally along the said base, the saidcarriage including tongs adapted to hold material to be drawn, anejector, means for mounting the said ejector on the said carriage formovement of said ejector through the said tongs, and a stop mounted onthe said fixed base, operating means for said ejector, the said stopbeing disposed in the path of the said operating means which engage thesaid stop and upon continued movement of the said carriage causes saidejector to move through the said tongs and, thereby, to remove the drawnmaterial from the said tongs upon abutting against the said stop.

2. A draw bench comprising in combination a fixed base, a carriageadapted to be moved longitudinally along the said base, the saidcarriage including tongs adapted to hold material to be drawn, jawsdisposed in the said tongs, an i ejector, means for mounting the saidejector on the said carriage for movement of said ejector through thesaid jaws, and a stop mounted on the said fixed base, operating meansfor said ejector, the said stop being disposed in the path of the saidoperating means which engage the said stop and upon continued movementof the said carriage causes the said ejector to move through the saidjaws and, thereby, to remove the drawn material from the said jaws uponabutting against the said stop.

3. A draw bench comprising in combination a fixed base, a carriageadapted to be moved longitudinally along the said base, the saidcarriage including tongs adapted to hold material to be drawn, jawsdisposed in the said tongs, a twoarmed lever pivctally mounted on thesaid carriage for movement of one arm of the said lever through the saidjaws in order to act as an ejector, and a stop mounted on the said base,the said stop being disposed in the path of the other arm of the saidtwo-armed lever which engages the said stop and upon continued movementof the said carriage causes said one arm to move through the said jawsand, thereby, to remove the drawn material from the said jaws uponabutting the said other arm against the said stop.

4. A draw bench comprising in combination a fixed base, a carriageadapted to be moved longitudinally along the said base, the saidcarriage including tongs adapted to hold material to be drawn, jawsdisposed in the said tongs, an ejector, means for mountin the saidejector on the said carriage for movement of said ejector through thesaid jaws, and a spring-loaded stop movably mounted on the said base,operating means for said ejector, the said stop being disposed in thepath of the said operating means which engage said stop and uponcontinued movement of the said carriage causes said ejector to movethrough the said jaws and, thereby, to remove the drawn material fromthe said jaws upon abutting against the said stop, means for movement ofthe said stop from its normal position upon the said material becomingjammed, and the said stop including means for stopping the movement ofthe said carriage upon movement of the said stop.

5. A draw bench comprising in combination a fixed base, a carriageadapted to be moved longitudinally along the said base, the saidcarriage including tongs adapted to hold material to be drawn, jawsdisposed in the said tongs, a twoarmed lever pivotally mounted on thesaid carriage for movement of one arm of the said lever through the saidjaws in order to act as an ejector, and a spring-loaded stop movablymounted on the said base, the said stop being disposed in the path ofthe other arm of the said two-armed lever which engages said stop andupon continued movement of the said carriage causes said one arm to movethrough said jaws and, thereby, to remove the drawn material from thesaid jaws upon abutting of the said other arm against the said stop,means for movement of the said stop from its normal positon upon thesaid material becoming jammed, and

the said stop including means for stopping the movement of the saidcarriage upon movement of the said stop.

6. A draw bench comprising in combination a fixed base, a carriageadapted to be moved longitudinally along the said base, the said carriage including tongs adapted to hold material to be drawn, jawsdisposed in the said tongs, a two-armed lever pivotally mounted on thesaid carriage for movement of one arm of the said lever through the saidjaws in order to act as an ejector, and a spring-loaded stop removablymounted on the said base, the said stop being disposed in the path ofthe other arm of the said two-armed lever and upon continued movement ofthe said carriage causes said one arm to move through the said jaws and,thereby, to remove the drawn material from the said jaws upon abuttingof the said other arm against the said stop, means for movement of thesaid stop from its normal position upon the said. material becomingjammed, an electric motor for driving the said carriage on the saidbase, an electric switch member for said electric motor disposed on thesaid carriage within the path of the movement of the said stop whichengages said switch member upon movement of the said step, the saidswitch member being operated and the said electric motor being stoppedby the movement of the said stop.

ALFRED KREIDLER.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 371,311 Gracey Oct. 11, 1887 989,109 Berning Apr. 11, 19111,080,793 Vold Dec. 9, 1913 1,574,381 Entenmann Feb. 23, 1926 2,182,902Nye Dec. 12, 1939 FOREIGN PATENTS Number Country Date 144,427 GermanySept. 30, 1903

